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sha512sum 2024-06-26 02:46:37 +00:00
parent 86b24ea926
commit 69b8276361
1 changed files with 9 additions and 13 deletions
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22
include/utempl/loopholes/counter.hpp
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@ -1,22 +1,21 @@
#pragma once
#include <utempl/loopholes/core.hpp>
#include <cstddef>
#include <tuple>
namespace utempl::loopholes {
namespace impl {
template <typename Tag, auto Value>
template <typename Tag, std::size_t Value>
struct TagWithValue {};
template <auto I = 0, typename Tag, typename... Ts, auto = Injector<TagWithValue<Tag, I>{}>{}>
constexpr auto Counter(...) {
return I;
};
template <auto I = 0, typename Tag, typename... Ts>
consteval auto Counter(std::size_t arg) requires Injected<TagWithValue<Tag, I>{}, Ts...> {
return Counter<I + 1, Tag, Ts...>(arg);
template <typename Tag, std::size_t I, typename... Ts>
consteval auto Counter() -> std::size_t {
if constexpr(requires{Magic(Getter<TagWithValue<Tag, I>{}>{});}) {
return Counter<Tag, I + 1, Ts...>();
};
return (std::ignore = Injector<TagWithValue<Tag, I>{}, 0>{}, I);
};
} // namespace impl;
@ -24,10 +23,7 @@ consteval auto Counter(std::size_t arg) requires Injected<TagWithValue<Tag, I>{}
template <
typename Tag,
typename... Ts,
std::size_t R = impl::Counter<0, Tag, Ts...>(std::size_t{})
#if defined __clang__
- 1
#endif
std::size_t R = impl::Counter<Tag, 0, Ts...>()
>
consteval auto Counter(auto...) -> std::size_t {
return R;